• Journal of Environmental Science International
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• v.22 no.7
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• pp.873-884
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• 2013

This study was carried out to establish the conservation plan of specific plants by surveying and analyse the individuals and the environment of habitats on specific plants designated by Juwangsan national park office. The specific plants were 14 species including Berchemia berchemiaefolia, Hylotelephium ussuriense, Aristolochia manshuriensis, Lilium cernuum, Thalictrum coreanum, Exochorda serratifolia, Lilium distichum, Aristolochia contorta, Jeffersonia dubia, Eleutherococcus senticosus, Salix chaenomeloids, Eranthis stellata, Scopolia japonica, and Paeonia japonica. The habitats of specific plants were 40 sites including Berchemia berchemiaefolia of 11 sites, Hylotelephium ussuriense of 8 sites, Lilium cernuum and Thalictrum coreanum of each 3 sites, Exochorda serratifolia of 2 sites, and Lilium distichum, Aristolochia contorta, Jeffersonia dubia, Eleutherococcus senticosus, Salix chaenomeloids, Eranthis stellata, Scopolia japonica and Paeonia japonica of each 1 site. The altitude was the most in 300~400 m. In direction, NW was the most, and it showed SW in that order. The slope angle was the most in 0~10%, and the cliff showed in that order. In the results of species composition by stratum layer, Berchemia berchemiaefolia had the most, 15 species, in tree layer. In shrub and herb layer, this had the most as 20 species and 29 species, too. The species that occupied the largest size was Salix chaenomeloids in 2,500 $m^2$, and Jeffersonia dubia showed 1,500 $m^2$ in that order. The conservation of specific plants is to accomplish the ex situ and in situ conservation at the same time.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.343-346
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• 2010

The construction plan of a combustion chamber test facility(CTF), a turbopump real propellant test facility(TPTF), a rocket engine ground/high altitude test facility(ReTF, HAReTF) and a propulsion system test complex(PSTC) for KSLV-II is briefly described. The development/qualification tests of 75ton-class liquid rocket engine system and engine component will be performed in CTF, TPTF, ReTF and HAReTF and the development test of $1^{st}/2^{nd}/3^{rd}$ propulsion systems for KSLV-II will be performed in PSTC. These propulsion test facilities will be built in NARO space center considering construction schedule, cost, safety distance and utility factor of propulsion test facilities.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.250-262
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• 2015

This study aims to investigate the characteristics of the vegetation structure in the sectin stretching between the Jilmoi wetlands and the Donghae Observatory and to set the criteria for the basic data for a management plan including restoration afterwards. 12 plots($10m{\times}40m$, $20m{\times}20m$) were set up to analyse the vegetation structure. The analysis of the classification by TWINSPAN and ordination by DCA, importance percentage and property, distribution of diameter of breast height, growth increments of major woody species, species diversity and the physicochemical properties of soil were all analyzed. Vegetation classes were divided into 3 communities, which are community I (Pinus densiflora community), community II (Quercus mongolica community) and community III (Quercus mongolica-Tilia amurensis community). The P. densiflora community declined when competing with Q. mongolica and Fraxinus rhynchophylla and Q. mongolica competed with T. amurensis on an understory layer in Q. mongolica community. Q. mongolica competed with T. amurensis on both canopy and understory layers in Q. mongolica-T. amurensis community. P. densiflora declined and it was assumed to succeed to F. rhynchophylla or T. amurensis through Q. mongolica based on the importance percentage and distribution of the diameter of the breast height of small and middle sized trees. The age of P. densiflora was between 47 to 51 years old and Q. mongolica was 61years old. T. amurensis was 61 years old and the growth of Q. mongolica slowed a little. As the result of Shannon's index of species diversity, community I ranged from 0.9578 to 1.1862, community II ranged from 0.7904 to 1.2286 and community III ranged from 0.8701 to 1.0323. The contents of organic matter and cation were low compared to uncultivated mountain soil and it were analysed to be inappropriate for tree growth.

• Journal of Astronomy and Space Sciences
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• v.33 no.4
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• pp.323-333
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• 2016

In this study, the uncertainty requirements for orbit, attitude, and burn performance were estimated and analyzed for the execution of the $1^{st}$ lunar orbit insertion (LOI) maneuver of the Korea Pathfinder Lunar Orbiter (KPLO) mission. During the early design phase of the system, associate analysis is an essential design factor as the $1^{st}$ LOI maneuver is the largest burn that utilizes the onboard propulsion system; the success of the lunar capture is directly affected by the performance achieved. For the analysis, the spacecraft is assumed to have already approached the periselene with a hyperbolic arrival trajectory around the moon. In addition, diverse arrival conditions and mission constraints were considered, such as varying periselene approach velocity, altitude, and orbital period of the capture orbit after execution of the $1^{st}$ LOI maneuver. The current analysis assumed an impulsive LOI maneuver, and two-body equations of motion were adapted to simplify the problem for a preliminary analysis. Monte Carlo simulations were performed for the statistical analysis to analyze diverse uncertainties that might arise at the moment when the maneuver is executed. As a result, three major requirements were analyzed and estimated for the early design phase. First, the minimum requirements were estimated for the burn performance to be captured around the moon. Second, the requirements for orbit, attitude, and maneuver burn performances were simultaneously estimated and analyzed to maintain the $1^{st}$ elliptical orbit achieved around the moon within the specified orbital period. Finally, the dispersion requirements on the B-plane aiming at target points to meet the target insertion goal were analyzed and can be utilized as reference target guidelines for a mid-course correction (MCC) maneuver during the transfer. More detailed system requirements for the KPLO mission, particularly for the spacecraft bus itself and for the flight dynamics subsystem at the ground control center, are expected to be prepared and established based on the current results, including a contingency trajectory design plan.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.771-775
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• 2010

This study was carried out to investigate soil and environment characteristics of Schizandra Chinensis Baillon habitat as a part of establishment of conservation plan for important medicinal crop resources in Jangsu-gun, Jeollabuk-do. These habitats are mostly located on the slopes of mountains facing northwest at an altitude of 500 m to 700 m with angles of inclination ranging from 17.6 to 36.4%. Average yearly precipitation and temperature of Schizandra Chinensis Baillon habitat were 1,493.4 mm and $16.9^{\circ}C$, respectively. The number of plant species growing in Schizandra Chinensis Baillon habitat was found 55 species. Salix gracilistyla, Lespedeza bicolor, and Artemisia princeps var. were shown higher density and coverage. Chemical quality of Schizandra Chinensis Baillon habitats soils was relatively higher than artificial cultivation soil.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.12
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• pp.1037-1048
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• 2018

In this paper, we investigated the international guidelines and actual disposal maneuver cases to prepare KOMPSAT-2 post mission disposal. And then, disposal maneuver plan was established using current propellant of KOMPSAT-2 and verification was also performed to find out whether the international guidelines are satisfied. As a result, the lifetime of KOMPSAT-2 was 3.6 years when 45kg propellant was used to decrease perigee altitude to 300km. And if more than 14.5kg propellant consumed for same strategy, KOMPSAT-2 can satisfy the international guidelines. Finally, re-entry survivability analysis was performed and it represented that heat resistant objects, such as propellant tank and reaction wheel, could be survived but total ground casualty probability was less than international guidelines.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.226-226
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• 2016

최근 이상기상현상과 기후변화로 인하여 국지적인 집중호우의 빈도 및 규모가 증가하고 있으며, 이로 인한 돌발 홍수피해가 증가하고 있다. 이러한 홍수 피해를 줄이기 위해서는 정확도가 우수한 초단시간(1~2시간 이내) 예측 강우량 정보가 필요하다. 본 연구에서는 집중호우에 대한 초단시간예보 및 실황 예측을 위해 시공간적으로 고해상도 자료를 제공할 수 있는 기상레이더 강우자료와 위성영상 자료를 결합하여 초단기 강수 예측기법 개발 연구를 수행하였다. 또한 기상레이더 강우량은 지상강우관측에 비해 정확성이 낮고, 많은 불확실성을 포함하고 있으므로, 위성영상에서 산출되는 강우자료와 결합하여 강우추정의 정확도를 개선하고자 하였다. 레이더 볼륨자료에서 반사도 자료를 추출하여, 1.5km CAPPI(Constant Altitude Plan Position Indicator) 자료를 생성하고, 반사도 CAPPI 자료의 패턴 상관분석을 통하여 강우시스템의 최적 이동벡터를 산출하였다. 또한 이동벡터를 고려하여 시공간적으로 외삽하여 강우이동 예측 모델을 개발하고, 초기자료로 레이더와 천리안 위성(Communication, Ocean and Meteorological Satellite, COMS) 영상자료에서 생성되는 강우자료를 결합한 강수장 자료를 이용하여 강수 예측장을 생성하였다. 레이더-위성 결합 초단기 강우예측 모델의 정확성 검증을 위하여 2014년 8월 25일 부산 및 영남 지역에 발생한 집중호우 사례에 대하여 지상기상자동관측시스템(Automatic Weather System, AWS) 강우 측정 결과를 비교 분석 하였으며, 그 적용 가능성을 검증하였다. 초단기 강우예측 분석 결과 지상강우자료와의 오차가 발생하나, 추후 여러 통계적 후처리 과정을 통하여 그 성능이 개선될 것으로 보이며, 보다 정확한 강우량 예측을 위해서는 지속적인 알고리즘 개선 및 모형의 검 보정이 필요할 것으로 사료된다.

• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.128-137
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• 2023

Purpose: This study proposes a way to improve quality and increase safety by studying a method that allows the system scaffolding, which is partly used for high-altitude work at construction sites, to be applied to various types of structures in shipbuilding and plant industry sites. Method: A fact-finding survey was conducted targeting 8 companies, and a plan was established that reflected the opinions of the field survey and the practitioners and experts by analyzing the literature and the Internet survey. Result: Through analysis of related patents, FGI with companies, etc., we discovered the possibility of application expansion through research and development of materials that can be applied to various types and improvement plans for enhancing the professionalism of construction companies. Conclusion: System scaffolding has a high importance in terms of safety, but related research around the world is sluggish. Therefore, it will be possible to meet the demands for quality and safety by enhancing the software expertise and developing and researching user materials that can be applied to various types.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.287-292
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• 2023

The U.S. National Aeronautics and Space Administration proposed a new concept of urban air mobility in the city's short-range air transport ecosystem in order to build a new low-altitude air, and the term uam is currently used worldwide. This paradigm is also being promoted by the Korean government with the goal of commercializing urban air transport services by 2025, and furthermore, the need to secure air maneuvers and transportation capacity is emerging due to the rapidly changing future operating environment and battlefield space. In other words, this study started to present the military necessity and military operation plan by introducing the 'Agility Prime' program of the US Air Force. 'Agility Prime' program was organized in order of background and concept of urban air mobility, development trend of Korean urban air mobility and analysis of the US Air Force's 'Agility Prime' program, and it is expected that this study will be followed by a follow-up study.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.38-44
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• 2023

This study aims to determine how agricultural drones are operated for flight tests using a 5G communication in order to carry out a mission such as sensing agricultural crop healthy status with special cameras. Drones were installed with a multi-spectral and IR camera to capture images of crop status in separate altitudes with different speeds. A multi-spectral camera can capture crop image data using five different particular wavelengths with a built-in GPS so that captured images with synchronized time could provide better accuracy of position and altitude during the flight time. Captured thermal videos are then sent to a ground server to be analyzed via 5G communication. Thus, combining two cameras can result in better visualization of vegetation areas. The flight test verified how agricultural drones equipped with special cameras could collect image data in vegetation areas.